Characterization of the two nonidentical ArgR regulators of Tetragenococcus halophilus and their regulatory effects on arginine metabolism

• Author(s) / Creator(s)

  • Lin, Jieting
  • Luo, Xiaotong
  • Gänzle, Michael G.
  • Luo, Lixin

• The halophilic lactic acid bacterium Tetragenococcus halophilus has been widely used in high-salinity fermentation processes of food. Previous studies have indicated that the catabolism of arginine may contribute to the osmotic stress adaptation of T. halophilus. Unusually, in the chromosome of T. halophilus, preceding the arginine deiminase (ADI) operon, locate two co-transcribed genes, both encoding an ArgR regulator; similar structure was rarely found and the roles of the regulators have not been demonstrated. In the current study, regulatory roles of these two nonidentical ArgR regulators on the arginine metabolism of T. halophilus were investigated. The results show that these two regulators play different roles in arginine metabolism, ArgR1 acts as a negative regulator of the ADI pathway by binding to the promoter sequences and repressing the transcription of genes, and the addition of arginine or hyper-osmotic stress conditions can abolish the ArgR1 repression, whereas ArgR2 negatively regulates the genes involved in arginine biosynthesis. Our study found that despite the commonly known roles of the ArgR regulators as the activator of arginine catabolism and the repressor of arginine biosynthesis, which are found in most studied bacteria possessed one ArgR regulator, the two nonidentical ArgR regulators of T. halophilus both act as repressors, and the repression by which is regulated when sensing changes of environments. By revealing the regulation of arginine metabolism, the current study provides molecular insights and potential tools for future applications of halophiles in biotechnology.

• Date created

  2020-01-01

• Subjects / Keywords

  • Tetragenococcus halophilus
  • ADI pathway
  • ArgR regulator
  • Osmotic stress

• Type of Item

  Article (Draft / Submitted)

• DOI

  https://doi.org/10.7939/r3-0xpm-7p84

• License

  © Springer-Verlag This version of the article has been accepted for publication, after peer review (when applicable) and is subject to Springer Nature’s AM terms of use, but is not the Version of Record and does not reflect post-acceptance improvements, or any corrections. The Version of Record is available online at: https://doi.org/10.1007/s00253-020-10868-6